Technical Field
The disclosure relates to a seal for a turbofan engine, and in particular relates to a seal for sealing a gap between a vane and a liner of an outlet guide vane.
Description of the Related Art
A turbofan engine is a jet engine of a type that has a bypass duct around an engine as a core. Part of energy generated by the engine drives a fan, part of an airflow generated by the fan is compressed by a compressor and then used for combustion in the engine while another part gushes out rearward directly through the bypass duct. The airflow through the bypass duct by itself produces thrust that contributes increase in engine thrust and also improves energy efficiency of the engine.
In the bypass duct provided are outlet guide vanes. The outlet guide vanes are a plurality of vanes elongated in respective radial directions and such vanes are arranged circumferentially to form a circular structure. The airflow generated by the fan is at first whirling flow but is, after passing through the outlet guide vanes, rectified into flow going straight rearward. As the outlet guide vanes may also function as a support that connects a fan case defining the bypass duct with the core portion, they require strength and stiffness required for such a function in addition.
Leakage of the airflow in the bypass duct to the exterior or mixture with secondary air should be avoided in view of efficiency of the fan. Therefore at any gaps between vanes and liners of the outlet guide vanes required are proper seals for sealing airflow therein.
The following documents disclose related arts.
Published Japanese Translation of PCT Application No. 2012-511661
Japanese Patent Application Laid-open No. H10-325303